What is a reverse proxy? | Proxy servers explained | Cloudflare
What is a reverse proxy?
A reverse proxy is a server that sits in front of web servers and forwards client (e. g. web browser) requests to those web servers. Reverse proxies are typically implemented to help increase security, performance, and reliability. In order to better understand how a reverse proxy works and the benefits it can provide, let’s first define what a proxy server is.
What’s a proxy server?
A forward proxy, often called a proxy, proxy server, or web proxy, is a server that sits in front of a group of client machines. When those computers make requests to sites and services on the Internet, the proxy server intercepts those requests and then communicates with web servers on behalf of those clients, like a middleman.
For example, let’s name 3 computers involved in a typical forward proxy communication:
A: This is a user’s home computer
B: This is a forward proxy server
C: This is a website’s origin server (where the website data is stored)
In a standard Internet communication, computer A would reach out directly to computer C, with the client sending requests to the origin server and the origin server responding to the client. When a forward proxy is in place, A will instead send requests to B, which will then forward the request to C. C will then send a response to B, which will forward the response back to A.
Why would anyone add this extra middleman to their Internet activity? There are a few reasons one might want to use a forward proxy:
To avoid state or institutional browsing restrictions – Some governments, schools, and other organizations use firewalls to give their users access to a limited version of the Internet. A forward proxy can be used to get around these restrictions, as they let the user connect to the proxy rather than directly to the sites they are visiting.
To block access to certain content – Conversely, proxies can also be set up to block a group of users from accessing certain sites. For example, a school network might be configured to connect to the web through a proxy which enables content filtering rules, refusing to forward responses from Facebook and other social media sites.
To protect their identity online – In some cases, regular Internet users simply desire increased anonymity online, but in other cases, Internet users live in places where the government can impose serious consequences to political dissidents. Criticizing the government in a web forum or on social media can lead to fines or imprisonment for these users. If one of these dissidents uses a forward proxy to connect to a website where they post politically sensitive comments, the IP address used to post the comments will be harder to trace back to the dissident. Only the IP address of the proxy server will be visible.
How is a reverse proxy different?
A reverse proxy is a server that sits in front of one or more web servers, intercepting requests from clients. This is different from a forward proxy, where the proxy sits in front of the clients. With a reverse proxy, when clients send requests to the origin server of a website, those requests are intercepted at the network edge by the reverse proxy server. The reverse proxy server will then send requests to and receive responses from the origin server.
The difference between a forward and reverse proxy is subtle but important. A simplified way to sum it up would be to say that a forward proxy sits in front of a client and ensures that no origin server ever communicates directly with that specific client. On the other hand, a reverse proxy sits in front of an origin server and ensures that no client ever communicates directly with that origin server.
Once again, let’s illustrate by naming the computers involved:
D: Any number of users’ home computers
E: This is a reverse proxy server
F: One or more origin servers
Typically all requests from D would go directly to F, and F would send responses directly to D. With a reverse proxy, all requests from D will go directly to E, and E will send its requests to and receive responses from F. E will then pass along the appropriate responses to D.
Below we outline some of the benefits of a reverse proxy:
Load balancing – A popular website that gets millions of users every day may not be able to handle all of its incoming site traffic with a single origin server. Instead, the site can be distributed among a pool of different servers, all handling requests for the same site. In this case, a reverse proxy can provide a load balancing solution which will distribute the incoming traffic evenly among the different servers to prevent any single server from becoming overloaded. In the event that a server fails completely, other servers can step up to handle the traffic.
Protection from attacks – With a reverse proxy in place, a web site or service never needs to reveal the IP address of their origin server(s). This makes it much harder for attackers to leverage a targeted attack against them, such as a DDoS attack. Instead the attackers will only be able to target the reverse proxy, such as Cloudflare’s CDN, which will have tighter security and more resources to fend off a cyber attack.
Global Server Load Balancing (GSLB) – In this form of load balancing, a website can be distributed on several servers around the globe and the reverse proxy will send clients to the server that’s geographically closest to them. This decreases the distances that requests and responses need to travel, minimizing load times.
Caching – A reverse proxy can also cache content, resulting in faster performance. For example, if a user in Paris visits a reverse-proxied website with web servers in Los Angeles, the user might actually connect to a local reverse proxy server in Paris, which will then have to communicate with an origin server in L. A. The proxy server can then cache (or temporarily save) the response data. Subsequent Parisian users who browse the site will then get the locally cached version from the Parisian reverse proxy server, resulting in much faster performance.
SSL encryption – Encrypting and decrypting SSL (or TLS) communications for each client can be computationally expensive for an origin server. A reverse proxy can be configured to decrypt all incoming requests and encrypt all outgoing responses, freeing up valuable resources on the origin server.
How to implement a reverse proxy
Some companies build their own reverse proxies, but this requires intensive software and hardware engineering resources, as well as a significant investment in physical hardware. One of the easiest and most cost-effective ways to reap all the benefits of a reverse proxy is by signing up for a CDN service. For example, the Cloudflare CDN provides all the performance and security features listed above, as well as many others.
What is a Reverse Proxy Server – Imperva
What is Reverse Proxy Server
A reverse proxy server is an intermediate connection point positioned at a network’s edge. It receives initial HTTP connection requests, acting like the actual endpoint.
Essentially your network’s traffic cop, the reverse proxy serves as a gateway between users and your application origin server. In so doing it handles all policy management and traffic routing.
A reverse proxy operates by:
Receiving a user connection request
Completing a TCP three-way handshake, terminating the initial connection
Connecting with the origin server and forwarding the original request
Reverse Proxy vs Forward Proxy
In contrast, a forward proxy server is also positioned at your network’s edge, but regulates outbound traffic according to preset policies in shared networks. Additionally, it disguises a client’s IP address and blocks malicious incoming traffic.
Forward proxies are typically used internally by large organizations, such as universities and enterprises, to:
Block employees from visiting certain websites
Monitor employee online activity
Block malicious traffic from reaching an origin server
Improve the user experience by caching external site content
How CDNs Use Reverse Proxies
Deployed at your network edge, content delivery networks (CDNs) use reverse proxy technology to handle incoming and outgoing traffic. Their benefits include:
Reverse proxies are placed in several geographically dispersed locations, where mirror versions of website pages are compressed and cached. This facilitates rapid content delivery based on client geolocation, helping to reduce page load times and improve your user experience.
Located in front of your backend servers, reverse proxies are ideally situated to scrub all incoming application traffic before it’s sent on to your backend servers.
DDoS mitigation – Incoming traffic is distributed among a mesh of reverse proxy servers during a DDoS attack to deflate its overall impact.
Web application security – Reverse proxies are an ideal location to place a web application firewall to weed out malicious packets—including bad bots and hacker requests.
When routing your incoming traffic through a reverse proxy server, connections are first terminated by the proxy and then reopened with the backend server. From your users’ perspective, their requests are resolved via the proxy IP.
As a result, your origin server’s IP address is masked. This makes it considerably more difficult for attackers to gain access and launch direct-to-IP denial of service attacks.
Because reverse proxy server are the gateway between users and your application’s origin server, they’re able to determine where to route individual HTTP sessions. For applications using multiple backend servers, this means the reverse proxy can efficiently distribute the load, thereby improving overall user experience and helping ensure high availability.
In the event that a server goes down, reverse proxies act as a failover solution, rerouting traffic to ensure continued site availability.
The Difference Between Proxy and Reverse Proxy | strongDM
Many businesses use proxy servers to route and secure traffic between networks. There’s often confusion, however, on how this differs from a reverse proxy. In this post, we’ll dissect the two concepts and explain how administrators can use a reverse proxy for easy access management is a proxy server? A proxy server, sometimes referred to as a forward proxy, is a server that routes traffic between client(s) and another system, usually external to the network. By doing so, it can regulate traffic according to preset policies, convert and mask client IP addresses, enforce security protocols, and block unknown stems with shared networks, such as business organizations or data centers, often use proxy servers. Proxy servers expose a single interface with which clients interact without having to enforce all of the policies and route management logic within the clients is a reverse proxy? A reverse proxy is a type of proxy server. Unlike a traditional proxy server, which is used to protect clients, a reverse proxy is used to protect servers. A reverse proxy is a server that accepts a request from a client, forwards the request to another one of many other servers, and returns the results from the server that actually processed the request to the client as if the proxy server had processed the request itself. The client only communicates directly with the reverse proxy server and it does not know that some other server actually processed its request. A traditional forward proxy server allows multiple clients to route traffic to an external network. For instance, a business may have a proxy that routes and filters employee traffic to the public Internet. A reverse proxy, on the other hand, routes traffic on behalf of multiple servers. A reverse proxy effectively serves as a gateway between clients, users, and application servers. It handles all the access policy management and traffic routing, and it protects the identity of the server that actually processes the verse proxy configurationBy routing client traffic through a reverse proxy, admins can simplify security administration. They can configure backend servers to only accept traffic directly from the proxy and then configure the granular access control configurations on the proxy example, admins can configure the reverse proxy’s firewall to whitelist or blacklist specific IP addresses. All existing servers behind the proxy will be protected accordingly, and whenever admins add a new backend server to the network that is configured to only accept requests from the proxy server, the new backend server is protected according to the proxy configuration. Using a reverse proxy can also allow administrators to easily swap backend servers in and out without disrupting traffic. Because clients interact directly with the proxy, they only need to know its host name and don’t need to worry about changes to the backend network topology. In addition to simplifying client configuration, an admin can configure a reverse proxy to load-balance traffic so that requests can be more evenly distributed to the backend servers and improve overall case: onboarding and off-boardingWhen onboarding a new user to a network, administrators must configure access control and firewalls to ensure the user can access the appropriate resources. Traditionally, an admin has to configure each server for which users need access. In a large organization with many servers, this can be a time-consuming and error-prone process. However, with a reverse proxy, administrators can configure the access rights directly on the proxy server and have the user route all traffic through it. As such, the backend servers only need to trust and communicate with the proxy directly. This greatly simplifies the configuration process and helps ensure access is granted and revoked correctly by doing so through a single tting up a reverse proxy for access managementWhile a reverse proxy can greatly simplify the process of managing access to a network, setting it up and configuring it properly can get complicated. It requires provisioning the host with appropriate specifications, configuring the operating system and firewall, deciding on which proxy software to use (such as NGINX or HAProxy), enumerating and configuring the downstream servers in the proxy configuration files, setting up audit logging, and configuring the firewalls in all the downstream servers. An administrator will need to optimize the proxy software to adjust for performance and availability requirements. For example, when a downstream server fails, the admin should configure the proxy server to quickly reroute traffic to avoid scale, the out-of-the-box configurations are rarely sufficient, so testing becomes important. Whenever the configurations change, you’ll need a way to run sufficient load against a representative test environment and closely monitor the impact on both performance and availability to verify that configurations will meet the needs of the production ing a reverse proxy by hand vs. buying softwareGiven all the steps involved in implementing, testing, and optimizing a reverse proxy, you may choose to buy software that can provide this functionality without all the custom work. Access management software can provide all of this functionality while also managing the ongoing maintenance and user management. In addition to providing standard reverse proxy capabilities, access management software affords a number of unique benefits:1) Flexibility with user access. By abstracting away the complexity of firewalls and access control, access management software can provide higher-level concepts like user groups. This functionality makes it easy for admins to assign and remove users from various predefined groups and allows the software to automatically implement the access policies. 2) Designed to boost reliability. In distributed systems, servers can fail and network interruptions may occur. Access management software easily detects failed servers and reroutes traffic to working ones to avoid any noticeable downtime for users. 3) Load balancing capabilities. Single servers may struggle when hit with a large amount of traffic, which degrades performance and increases request latency. Access management software can help to manage traffic and balance the load across all servers, making sure it’s evenly naging access with strongDMThe strongDM control plane is a proxy-based solution that simplifies authentication and authorization for admins. It routes all database and server connections through its protocol-aware proxy over a TLS 1. 2 secure TCP connection, and it handles load balancing and automatic failover to provide high availability. The proxy validates user sessions and permissions and then intelligently routes the session to the target database or server through the most efficient path, logging all traffic along the rongDM extends the single sign-on capabilities of your identity provider, allowing you to authenticate users to any server or database. From the Admin UI, you can view connected resources and manage role-based access control for your users. See for yourself with a free, 14-day trial. this post? Then get all that SDM goodness, right in your you! Your submission has been received! Oops! Something went wrong while submitting the form.
Frequently Asked Questions about reverse proxy protocol
What is a reverse proxy server used for?
A reverse proxy server is an intermediate connection point positioned at a network’s edge. It receives initial HTTP connection requests, acting like the actual endpoint. Essentially your network’s traffic cop, the reverse proxy serves as a gateway between users and your application origin server.
What is the difference between proxy and reverse proxy?
A traditional forward proxy server allows multiple clients to route traffic to an external network. … A reverse proxy, on the other hand, routes traffic on behalf of multiple servers. A reverse proxy effectively serves as a gateway between clients, users, and application servers.Mar 31, 2021
What is reverse proxy and how does it work?
A reverse proxy server is a type of proxy server that typically sits behind the firewall in a private network and directs client requests to the appropriate backend server. A reverse proxy provides an additional level of abstraction and control to ensure the smooth flow of network traffic between clients and servers.